Perris R, Johansson S
Department of Zoology, Uppsala University, Sweden.
J Cell Biol. 1987 Dec;105(6 Pt 1):2511-21. doi: 10.1083/jcb.105.6.2511.
The ability of purified extracellular matrix components to promote the initial migration of amphibian neural crest (NC) cells was quantitatively investigated in vitro. NC cells migrated avidly on fibronectin (FN), displaying progressively more extensive dispersion at increasing amounts of material incorporated in the substrate. In contrast, dispersion on laminin substrates was optimal at low protein concentrations but strongly reduced at high concentrations. NC cells were unable to migrate on substrates containing a high molecular mass chondroitin sulfate proteoglycan (ChSP). When proteolytic peptides, representing isolated functional domains of the FN molecule, were tested as potential migration substrates, the cell binding region of the molecule (105 kD) was found to be as active as the intact FN. A 31-kD heparin-binding fragment also stimulated NC cell migration, whereas NC cells dispersed to a markedly lower extent on the isolated collagen-binding domain (40 kD), or the latter domain linked to the NH2-terminal part of the FN molecule. Migration on the intact FN was partially inhibited by antibodies directed against the 105- and 31-kD fragments, respectively; dispersion was further decreased when the antibodies were used in combination. Addition of the ChSP to the culture medium dramatically perturbed NC cell migration on substrates of FN, as well as of 105- or 31-kD fragments. However, preincubation of isolated cells or substrates with ChSP followed by washing did not affect NC cell movement. The use of substrates consisting of different relative amounts of ChSP and the 105-kD peptide revealed that ChSP counteracted the motility-promoting activity of the 105-kD FN fragment in a concentration-dependent manner also when bound to the substrate. Our results indicate that NC cell migration on FN involves two separate domains of the molecule, and that ChSP can modulate the migratory behavior of NC cells moving along FN-rich pathways and may therefore influence directionally and subsequent localization of NC cells in the embryo.
体外定量研究了纯化的细胞外基质成分促进两栖类神经嵴（NC）细胞初始迁移的能力。NC细胞在纤连蛋白（FN）上积极迁移，随着底物中掺入的物质数量增加，呈现出越来越广泛的分散。相反，在层粘连蛋白底物上的分散在低蛋白浓度时最佳，但在高浓度时显著降低。NC细胞无法在含有高分子量硫酸软骨素蛋白聚糖（ChSP）的底物上迁移。当测试代表FN分子分离功能域的蛋白水解肽作为潜在的迁移底物时，发现该分子的细胞结合区域（105 kD）与完整的FN一样具有活性。一个31-kD的肝素结合片段也刺激了NC细胞迁移，而NC细胞在分离的胶原结合域（40 kD）或与FN分子NH2末端相连的后一个域上的分散程度明显较低。在完整的FN上的迁移分别被针对105-kD和31-kD片段的抗体部分抑制；当联合使用抗体时，分散进一步减少。向培养基中添加ChSP显著扰乱了NC细胞在FN以及105-kD或31-kD片段底物上的迁移。然而，将分离的细胞或底物与ChSP预孵育然后洗涤并不影响NC细胞的运动。使用由不同相对量的ChSP和105-kD肽组成的底物表明，当ChSP与底物结合时，它也以浓度依赖的方式抵消了105-kD FN片段的促运动活性。我们的结果表明，NC细胞在FN上的迁移涉及该分子的两个独立域，并且ChSP可以调节沿着富含FN途径移动的NC细胞的迁移行为，因此可能影响胚胎中NC细胞的定向和随后的定位。
